<topic>
	<head>
		<title>CONCAT</title>
		<keywords>
			<keyword term="functions, CONCAT" />
			<keyword term="aggregates, CONCAT" />
			<keyword term="aggregate functions, CONCAT" />
			<keyword term="CONCAT aggregate" />
		</keywords>
		<links>
			<link href="Functions.html">Functions</link>
			<link href="Aggregate Functions.html">Aggregate Functions</link>
		</links>
	</head>
	<body>
		<summary>
			<p>
				Returns a comma separated list of the string representations of the values in a group. <c>NULL</c> values are ignored.
			</p>
		</summary>

		<syntax>
			<code xml:space="preserve">CONCAT ( expression )</code>
		</syntax>

		<parameters>
			<params>
				<param name="value">
					<p>
						An expression to produce a comma separated list of. <c>expression</c> can be of any data type.
					</p>
				</param>
			</params>
		</parameters>

		<remarks>
			<p>
				The comma separated list returned by <c>CONCAT</c> is sorted and contains no duplicates.
			</p>
		</remarks>

		<returns>
			<p>
				The comma separated list of the string representations of all evaluated values of <c>expression</c> in a group.
				<c>NULL</c> values are ignored.
			</p>
		</returns>

		<examples>
			<p>
				The following sample performs an aggregation of employees grouped by city. The <c>CONCAT</c> aggregate is used to create
				a comma separated list of all employees living in the same city.
			</p>
			<sampleCode language="NQuery.SQL" xml:space="preserve">  SELECT e.City,
         CONCAT(e.FirstName + ' ' + e.LastName) AS Employees
    FROM Employees e
GROUP BY e.City
</sampleCode>
		</examples>
	</body>
</topic>
